Air-pump piston



Patented Mar. '13, i923.

nutren stares rattan WILLIAIII COFFIN COLEMAN, F WICHITA, KANSAS.

Application filed July 2, 1921. Serial No. 482,013.

To all lwhom t may concern.'

Be it known that I, VILLIAM CorrIN COLEMAN, a citizen of the United States, residing at lVichita, in the county of Sedgwick and State of Kansas, have invented certain new and useful Improvements in Air-Pump Pistons; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make'and use the same, reference being had to the accompanying drawings, and to the figures of reference marked thereon, which form a part or this speciiication.

This invention relates to pump pistons and particularly to a piston for air pumps generally employed for inflating tires.

One of the objects of the invention is to provide a simple, durable and efficient construction of pumppiston which may be readily attached to the piston rod which constitutes a part thereof, and the primary object is to so construct the piston and the rod that the assembly of the various parts will be facilitated.

I have reduced the number of parts to a minimum and so constructed the various coordinating elements that the assembling can be accomplished by persons having no particular skill, thereby enabling the piston to be constructed at a relatively low cost and yet have a maximum efliciency.

In the drawings,

Fig. 1 is a vertical, longitudinal, sectional view through a pump cylinder and piston,

the piston being constructed in accordance with my invention, and

Fig. 2 is a similar view of a slightly modified form of piston.

The piston rod 1 is shown as provided with a constricted end 2 to provide a shoulder 3, against which may abut a cover plate 4 in the form of a disk having perforations 5 therethrough. The disk also serves as a clamping member for clamping the pump leather 6 between it and a complementary clamping member 7, shown as a casting threaded on the end of the constricted portion 2, as at 8. The complementary member 7 is provided with an annular groove 9 on its upper face, formed by the boss 10 and the upstanding circumferential flange 11, which extends slightly beyond the boss to The chamber is, in effect, a valve cage in which is located a reciprocatory -disk valve 13, sleeved on the 'constricted portion 2 of the stem or rod 1 and adapted to move toward and away from the cover plate or disk 4. The member 7 maybe cast with an air opening 14 therein .so that when the piston 1s reciprocated in an upward direction or an outward direction, the air may enter through the ports 5, through the valve cage and through the port14 into the compression chamber 15 ofthe pump cylinder 16. Thisfaction will take place because the disk valve is of less diameter thanthe diameter of the valve cage or chamber so that the air can flow around it. On the down stroke or compression stroke of the pisto-nhowever, the disk valve will close the openings 5 `so that the air may be compressed within the chamber 15 and discharged through the diS- charge opening 17, past the outwardly opening valve 18, through the oil trap 19 in the base 20 and through theopen port 21 tothe tire or other device to receive the compression.

The particular construction of the oil trap and pump in its generic aspect constitutes the subject matter of another-application, executed by me of even date herewith, Serial y No. 482,012, filed July 2, 1921, this application being limited to the piston per se.

In the modilied form shown in Fig. 2, the i piston rod 1 is provided with a constricted portion 2, forming a shoulder 3 and a clamping disk 4 having openings 5, and the plate 4 may clamp the leather 'between it and the complementary member 7. l

In this form the member 7 has athrough port 14 forming a valve cage for the ball y valve 10 held therein by the pin 22. 'When the piston moves on its out stroke, the valve will rest on the pin 22 so thatair may enter through the openings 5 through the chamber or valve cage 14 into the compression chamber 15 of the cylinder 16 and upon the compression stroke, the valve will seat on the seat 23, closing the inletopening 24 so that theair can be compressed in the chamber 15 and forced out through the port 17, past the valve 18, to the tire or other devices designed to contain the compressed air.

It Will be apparent from the foregoing that a device constructed in accordance With my invention is simple, inexpensive and that the part-s may be quickly and easily assembled to provide a rigid efficient structure.

TWhat I claim and desire to secure by Letters-Patent is:

l. A pump piston comprising a piston rod, a cover plate thereon, a complementary clampingmember, the cover plate having air openings and the complementary member being provided with air openings, the complementary.member also having` anv annular chamber, the floor of which is spaced away from the cover plate to provide a valve cage, and a reciprocat-ory flat valve Within the chamber and sleeved upon the piston rod.

2. A pump pistonk comprising a piston rod, a cover plate thereon, al complementary clamping member, the cover-plate having air openings and the complementary member being provided with air openings, the complementary member also having an annular chamber, the foor of which is spaced away from the cover plate to provide a valve cage, a reciprocatory flat valve Within the chamber and sleeved upon the piston rod, and a pump leather clamped between the cover plate and the complementary member.

ln testimony whereof l affix my signature.

VILLIAM COFFIN COLEMAN. 

